Vernier Pulley For Standard Xu 8 Valve

[ALEX 98 1 Cars]

These are usually fitted to fine tune aftermarket Cams, but is there any benefit in fitting one to a stock Cam or a Stock cam?

 

I ask because my 1.6 Cti, which has far from the original engine XU5JA that is supposed to be in the car (not all my doing) sounds like it's detonating in the exhaust manifold at tick over.

Though at about 1200 RMP + it sounds fine. Altering the ignition timing (dizzy angle) doesn't make any difference with regards to the detonating sound,

Tick over is fairly smooth for an old car and the performance is as expected, but the sound is a bit of a disappointment, like a leaky exhaust manifold. (It's not leaking).

 

The head at least is the 180A type. I think the bottom end is original but I can't remember if the pistons were shaped (Dist arrow) or not. All this revelation came after I built the engine BTW!

The head has been lightly skimmed (clean up), and I learnt off here a higher comp ratio is preferred anyway so I fitted an original thickness gasket.

 

Hence I'm wondering if fitting a vernier pulley would tune out the detonation at tick over?

 

[dcc 855]

what fuel are you using, is the cti meant to be cat equipt, is it a standard exhaust, what spark plugs, what cr is it running?

 

My understanding is a heavy skim can alter the timing slightly, potentially enough to require a few degree of alteration. you might have already had a skim on the head before you touched it.

[ALEX 98 1 Cars]

Its the non cat 1.6. (f plate) Been using super unleaded.

There's a few pics of the engine build in my sig.

I learnt more about the engine after I did the rebuild. I assumed the engine was original at the time, turns out it wasn't as all Ctis should have the XU5ja engine.

Chances are the head had been skimmed before, but is there a way of telling with the head fitted?

as for CR, not a clue

[welshpug 1,629]

180a is a fairly early 1.6, no age of 1.6 ever had a cat.

 

its unlikely to be detonation, but pinking is possible,

[ALEX 98 1 Cars]

Just remembered Spark plugs were bought by giving my reg plate.!

Are they different for the XU5J (180A) to XU5JA?

[welshpug 1,629]

Model Detail Engine Type / Additional Info Year Part No Stock No

205 1.6 Incl. Gti > 12/87 BP6EF 4666

205 1.6 NON-CAT Incl. Gti 01/88 > BCP6E 5860

205 1.6 CATALYST Incl. GTi 10/91 > BCPR6E 1269

 

I doubt you will notice much difference between those, for reference 1.9 used as follows:

 

 

Model Detail Engine Type / Additional Info Year Part No Stock No

205 1.9 NON-CAT Incl. Gti 86 > 90 BCP7ES 5030

205 1.9 CATALYST Incl. GTi 90 > BCPR6E 1269

 

 

 

 

 

 

1.9 405's

 

Model Detail Engine Type / Additional Info Year Part No Stock No

405 1.9 incl. SRI 01/88 > 10/92 BCPR6E 1269

405 1.9 XU9J4-D6C / Mi-16 (NON-CATALYST) 01/88 > 10/92 BCP7ET 2078

405 1.9 XU9J4-D6C / Mi-16 (CATALYST) 01/90 > 07/92 BCPR6ET 2197

 

2.0 405's

 

Model Detail Engine Type / Additional Info Year Part No Stock No

405 2.0 - 10/92 > 95 BCPR6E 1269

405 2.0 - 95 > 02/97 BKR6EK 2288

405 2.0 XU10J4Z-RFY / Mi-16 12/92 > BKR6EK 2288

 

 

 

 

 

 

 

2.0 306's

 

306 2.0 XU10J2 / SOHC 01/94 > 06/97 BCPR6E 1269

306 2.0 XU10J4 / DOHC (incl S16 & GTi 6) 01/94 > 09/99 BKR6EK 2288

306 2.0 - 09/99 > 06/01 BKR6EZ 4619

NGK Spark Plugs / NTK Technical Ceramics